Muffler construction



Feb. 25, 1941. CARY 2,233,341

MUFFLER CONSTRUCTION Filed July 27, 1938 Patented Feb. 25, 1941 MUFFLERCONSTRUCTION Beecher B. Cary, Jackson, Mich, minor to Hayes Industries,Inc.; Jackson, Mich, a corporation of Michigan Application July 27,1938, Serial No. 221,471

Clainii'l 181-48) This invention relates to improvements in theconstruction of mufflers and more particularly to mufflers for silencingthe noises of the exhaust or intake of internal combustion engines.

5 Present day muffler constructions comprise for the most part anarrangement of tubular members, shells and bames so-as to formresonating chambers and the like, having different characteristics forthe attenuation of the diflerent frequency tones found in" the intake orexhaust gases, as the case may be. According to the present invention,the manufacture of mufflers is simplified by providing resonatingchambers having end and side walls comprised of integral sections. Inits specific form the resonating chambers fabricated according to thepresent invention may comprise two oppositely disposed abutting cupshaped members or a single cup shaped member abutting against a membersuch m as a baiiie.

An object of the invention is to provide resonating chambers formulflers having integral side and end portions.

Another obiect of the invention is to provide resonating chambers formufflers by stamping cup shaped members and disposing them aboutperi'orated gas carrying tubes.

Still another object of the invention is to provide a muflierconstruction having a resonating chamber having an integral baflieassociated therewith, said baiiie being in a second resonating chamber.

These and other objects will be apparent from the followingspecification when taken with the accompanying drawing wherein thefigure illustrates a single muflier employing two embodiments of thepresent invention.

Referring particularly to the drawing, the reference character Iindicates the outer shell of a mufller having sections broken outtherefrom and showing only as part thereof two embodiments of thepresent invention. The shell I isprovided with heads 2 and 3 having,respectively, .inlet and outlet connections 4 and 5. The mufllerdisclosed is of the straight through type and has concentricallydisposed within the shell I a straight through tube 6. The tube 8 isprovided with a plurality of perforations I of any desired character.

Disposed about the tube 8 and enclosing certain of the perforations I isa resonating chamber 8 having walls consisting of two cup shaped members9 and I0. Each cup shaped member 9 and II) has a tubular portion II, anoutwardly projecting radial flange I2, an inwardly projecting radialflange I3, and an axially extending annular flange I4. The annularflanges I4 are in circumferential engagement with the periphery of thetube 8 and are telescopically related thereto. In manufacture, theflanges ll are originally of such a diameter as to permit them to slideover the perforations I, after they have been arranged on the tube 8, asdisclosed in the drawing. They are reduced in diameter in a manner wellknown in the art, usually by crimping excess metal to bring them intothe snug engagement with the tube 8 asdisclosed. The radially projectingflanges I2 abut against one another. The annular flanges II and the tube0 are connected together, as by spot welding, as are the outwardlyprojecting, radially extending flanges I2, the respective joints beingcontinuous to provide substantially gas tight connections. One of theflanges I2 is provided with an extension I5, having at the peripherythereof an annularly axially extending portion I8 telescopicallydisposed within the shell I, contiguous with the inner surface thereof,and secured thereto as by spot welding.

From the description thus far it will be evident that the flanges I3 andtubular portions II form the walls of the chamber 8 about a portion ofthe tube 6, the chamber 8 being a resonating chamber for attenuatinghigh frequency tones, since it is relatively small in size. Also, theflanges I2 and the extension I5, together with the flanges I3, comprisea ballie within the shell I, dividing the shell I into chambers 20 and2I. It will be understood, however, that as far as the present inventionis concerned the flanges I2 and extension I5 may be dispensed with if acomplete battle in the shell I is not desired.

Another form which the invention may take comprises the member 22disposed about the tube 6 and certain other of the perforations I. Themember 22 comprises a tubular portion 23, a generally inwardly extendingflange 24, and an axially extending annular flange 25 integrallyassociated with the flange 24 and telescopically disposed about the tube6 in circumferential contact with the periphery thereof. The flanges 25are brought into snug engagement with the tube Ii in the same manner asthe flanges I4. As in the case of the flanges I4, the flange 25 issecured to the tube 6, as by spot welding, for instance.

The opposite end of the member 22 is open and abuts against the head 3.To provide a more tight seal between the member 22 and the head 3 thehead 3 is provided with a cylindrical portion 28 in which the tubularportion 23' of the member I! is telescopically received, after which thetubular portion 23 may be secured as by spot welding. An advantage ofthe member 22 is that before securing'the same to the tube and the headI, it may be adjusted axially with respect to the tube 0 to vary thesize of the chamber for which it provides walls and thus tune themuiiier to take out a particular frequency tone. If desired, the member22 may be provided with openings 21, which may be varied as to size andnumber for further tuning.

The members 9, II and 22, are preferably formed from sheet metal bystamping and drawing. Their use not only makes possible the building upof a resonating chamber from a fewer number of parts than heretoforethought possible, but also reduces the amount of material required andthe labor required in assembling.

mufiier constructions. While the invention has been disclosed as appliedto a straight through type of muiiier having a single shell thereabout,it will be understood that the principle thereof need not be so limited,but may be applied to other portions of other or more complex mui'flerstructures. As an example, the members 0 and I. or 22 may be applied togas conducting tubes other than straight through tubes of the characterof the straight through tube ii illustrated in the drawing.

Having thus described my invention, what I desire to secure by LettersPatent and claim is:

i. In a muiller of the character described, a tube having a plurality ofperforations therein, a shell surrounding said tube, a member disposedabout said tube and within said shell overlapping said perforations,said member having two abutting tubular portions spaced from said tubeand substantially concentrically related thereto, integral end portionsat opposite ends of said tubular portions, said end portions havingsubstantially concentric openings therein receiving said tube, saidtubular and end portions comprising walls of a chamber disposed aboutsaid tube, and a flange comprising an angularly disposed integralcontinuation of one of said tubular portions, said continuation havingits periphery in engagement with said shell and comprising a bailietherein.

2. In a mu'iiier of the character described, a tube' having a pluralityof perforations therein, a member disposed about said tube overlappingsaid perforations, said member having two abutting tubular portionsspaced from said tube and substantially concentric with respect thereto,said tubular portions at their inner ends having radially extendingflanges in abutting relation and at their outer ends radially inwardlyextending flanges having substantially concentric openings therethroughreceiving said tub, one of said abutting flanges having its periphery inengagement with said shell comprising a baiiie therein, said tubular andend portions comprising walls of a chamber disposed about said tube.

3. In a muffler of the character described, a tube having a plurality ofperforations therein, a shell disposed thereabout substantiallyconcentric therewith, a member disposed about said tube overlapping saidperforations, said member having a tubular portion spaced from said tubeand an integral angularly inwardly extending portion having asubstantially concentric opening therein receiving said tube, and apartition within said shell having a concentric opening thereinreceiving'said tube, said member having one end thereof abutting againstsaid partition, said member and a portion of said partition comprisingthe walls of a chamber disposed about said tube.

4. In a muiller of the character described, a tube having a plurality ofperforations therein, a member disposed about said tube overlapping saidperforations, said member having a tubular portion spaced from said tubeand an integral, angularly related, inwardly extending portion having asubstantially concentric opening therein receiving said tube, and abaille having a concentric opening therein receiving said tube, saidbaiile having a portionthereof offset to provide a tubular portion forreceiving the tubular portion of said member, said tubular portionsbeing telescopically related and in circumferential contact.

5. In a straight through muffler of the acoustic resonator type, thecombination with a periorated through tube having an outer shell spacedtherefrom, of a combined thin walled bai'ile and high frequencyresonator chamber comprising a pair of opened end cup shaped sheet metalstampings having openings in the closed ends thereof to closely embracesaid through tube, said stampings being located upon said through tubein opposed relation to each other with their open ends-in abuttingrelation to collectively form a high frequency resonator chamberembracing a perforated portion of said through tube and spaced inwardlyfrom said outer shell, at least one of said stampings supporting aradial flange extending from said resonator chamber to said outer shellto form a thin wall baiile embracing said resonator chamber and dividingthe chamber between said outer shell and said through tube into aplurality of lower frequency resonator chambers.

BEECKER B. CARY.

